Zhian came to the door, and Soo Hyuk called her to say that the biological reaction was a misjudgment, and she had to go back to meet the two and remind her not to act alone. Qixiu got the sample and found that it was water. When Zhian hurried back, Qixiu opened the door of the storage room, but was arrested immediately. Zhian went in to check and found that Qixiu was caught and strangled to death and fell down. Someone was caught. Taking the sample from his hand, Soo Hyuk rushed to inform the others. Jia Rong said that the cause of death was a fracture of the cervical spine and multiple fractures on his body. It was not like falling to death from a height. Yunjae asked why Zhian didn’t follow Qi. Xiu acted together and took her portable secret recorder to check the monitor. Kim Sun realized that Xiucan was weird. Suddenly, water came out of Xiucan’s mouth. Yunjae found a ventilation duct beside Qixiu’s body, but suddenly received the news from Xiucan and rushed back. Jiarong asked for something else. People put on protective clothing and inserted a tube around Xiucan's neck to let him drain the water. When the blood was drawn, it was found that it was all water. Soon after, Xiucan died, just like being drowned.
Jia Rong said that he would have an autopsy immediately, and Ji An also said that he would check the records, and Yunjae, Soohyuk and E2 went to check the ventilation ducts, and asked Tae-seok and Kim Sun to find a way to restore communication. Zhian checked the record and found no abnormalities. Suddenly saw her sister’s encrypted record. She told E1 that she was going to obtain the tissues of other corpses. E1 said that she wanted to accompany her. E1 collects tissues by himself. E1 is worried that he will be infected, so Zhian takes the opportunity to go to the information repository. Yunjae and others found eye graffiti in the ventilation pipe, and suddenly a biological signal approached. The three people found a first-level control area that they did not have permission to enter. Tae-seok suddenly said that he found a way to communicate, but someone must go outside to correct the device at the same time. Inside, Yuncai said he was going. Zhian said that the intruder didn't want to kill her and was familiar with the internal structure. He guessed it was a survivor, but Yunjae said it was impossible.